Medical laser system

ABSTRACT

A medical laser system includes a crystal-based laser, an electrosurgery or electrocautery device, a power supply for powering the crystal-based laser and the electrosurgery or electrocautery device, and a controller operably connected to the crystal-based laser, the electrosurgery or electrocautery device, and the power supply. The controller is programmed to: (a) activate the crystal-based laser by controlling power supplied by the power supply to the laser responsive to a laser activation input by a user; and (b) activate the electrosurgery or electrocautery device by controlling power supplied by the power supply to the electrosurgery or electrocautery device responsive to an electrosurgery or electrocautery device activation input by the user.

This application claims priority from U.S. Provisional PatentApplication No. 62/312,272 filed on Mar. 23, 2016 entitled MEDICAL LASERSYSTEM, which is hereby incorporated by reference.

BACKGROUND

Surgical lasers are a well-known alternative to scalpels, curettes, andother mechanical tools used to surgically remove tissue. Directingintense near infrared (NIR) laser light onto tissue can cause the tissueto vaporize, burn, be ablated, or otherwise be cut. Less intense NIRlaser light can be used to cause coagulation or cauterization.

Laser surgical instruments are often bulky and difficult to move fromone operating venue to another. A need exists for an improved surgicallaser, for example, a surgical laser with decreased size and/or betterreliability.

SUMMARY

A medical laser system in accordance with one or more embodimentsincludes a crystal-based laser, a power supply for powering thecrystal-based laser, a controller operably connected to thecrystal-based laser and the power supply, and a liquid cooling system.The liquid cooling system includes a conduit circuit through which acooling liquid can circulate. The conduit circuit is thermally coupledto the crystal-based laser such that the cooling liquid in the conduitcircuit absorbs heat from the crystal-based laser. One or more heatsinks are coupled to the conduit circuit and to the power supply suchthat the cooling liquid in the conduit circuit absorbs heat from thepower supply. A pump is provided for driving the cooling liquid throughthe conduit circuit. A heat exchanger cools the cooling liquid in theconduit circuit.

A medical laser system in accordance with one or more furtherembodiments includes a crystal-based laser, a power supply for poweringthe crystal-based laser, a controller operably connected to thecrystal-based laser and the power supply, and a memory operablyconnected to the controller. The controller is programmed to: (a)activate the crystal-based laser to cause a laser light emission bycontrolling power supplied by the power supply to the laser responsiveto a user activation input; and (b) record data in the memoryidentifying a power level, number of pulses, and duration of the laserlight emission.

A medical laser system in accordance with one or more furtherembodiments includes a crystal-based laser, an electrosurgery orelectrocautery device, a power supply for powering the crystal-basedlaser and the electrosurgery or electrocautery device, and a controlleroperably connected to the crystal-based laser, the electrosurgery orelectrocautery device, and the power supply. The controller isprogrammed to: (a) activate the crystal-based laser by controlling powersupplied by the power supply to the laser responsive to a laseractivation input by a user; and (b) activate the electrosurgery orelectrocautery device by controlling power supplied by the power supplyto the electrosurgery or electrocautery device responsive to anelectrosurgery or electrocautery device activation input by the user.

A medical laser system in accordance with one or more furtherembodiments includes a crystal-based laser configured, when activated,to emit laser light having wavelength in the range of 1000 to 2000nanometers. The system also includes a pointer laser configured, whenactivated, to emit visible green or blue laser light having a wavelengthin the range of 400 to 620 nanometers. The pointer laser and thecrystal-based laser are configured to be focused on a common targetposition. The system also includes a power supply for powering thecrystal-based laser and the pointer laser and a controller operablyconnected to the power supply, the crystal-based laser, and the pointerlaser. The controller is programmed to: (a) activate the crystal-basedlaser by controlling power supplied by the power supply to the laserresponsive to a laser activation input from a user; and (b) activate thepointer laser by controlling power supplied by the power supply to thepointer laser responsive to a pointer laser activation input from theuser.

A method of using a surgical laser system in accordance with one or morefurther embodiments includes the steps of: (a) positioning an emissionport of the laser system at a predetermined cutting distance from atissue to be cut; (b) cutting the tissue to be cut by activating thelaser system while the emission port is at the predetermined cuttingdistance from the tissue to be cut; (c) positioning the emission port ata predetermined coagulation distance from a tissue to be coagulated, thecoagulation distance being greater than the cutting distance; and (d)coagulating the tissue to be coagulated by activating the system whilethe emission port is at the predetermined coagulation distance from thetissue to be coagulated.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically illustrates an exemplary cooling system for amedical laser in accordance with one or more embodiments.

FIG. 2 is a cross-section view of an exemplary liquid cooled heat sinkin the cooling system of FIG. 1 in accordance with one or moreembodiments.

FIG. 3 schematically illustrates an exemplary control system for amedical laser in accordance with one or more embodiments.

FIG. 4 schematically illustrates an exemplary control system for a laserand electrosurgery or electrocautery system in accordance with one ormore embodiments.

FIG. 5 schematically illustrates an exemplary laser head configurationof a medical laser in accordance with one or more embodiments.

DETAILED DESCRIPTION

FIG. 1 schematically illustrates an exemplary liquid cooling circuit 10in a medical laser system in accordance with one or more embodiments.The liquid cooling circuit comprises a closed conduit circuit 12 throughwhich cooling liquid flows, a pump 14, one or more cooling plates 16,18, 20, 22, a heat exchanger 24, a filter 26, and a liquid replenishmenttank 28. The cooling liquid inside the circuit absorbs heat from a laserhead 30 and the one or more cooling plates. Heated liquid is transportedto the heat exchanger, which cools the liquid.

The cooling liquid can comprise a variety of heat transfer fluidsincluding, e.g., water including deionized water and distilled water.

The pump 14 can comprise a variety of pumps including, e.g., a magneticdrive pump. In the exemplary embodiment of FIG. 1, the pump drives theliquid through the circuit in a counterclockwise direction as indicatedby the flow arrows.

The cooling circuit is coupled to the laser head such that coolingliquid can flow through the laser head housing in thermal contact withthe laser components therein.

The cooling fluid can also be in thermal contact with other componentsof the medical laser system. As shown in FIG. 1, the cooling liquid isthermally coupled with the thermally conductive cooling plates 16, 18,20, 22. The cooling plates are in thermal contact with various othercomponents of the laser system in need of temperature regulationincluding, e.g., a power supply 32, capacitors, and other electronics.Although the system is shown with four cooling plates, any number ispossible. FIG. 2 is a cross-section view of an exemplary cooling plate16 having a conduit 42 embedded therein carrying the cooling liquid.

Cooling liquid in the fluid circuit can be replenished, as needed, withadditional liquid from a replenishment tank 28. The cooling liquid tankincludes a coolant level sensor 34 and an inlet 36 for receivingadditional liquid as needed.

The filter 26 removes any particles in the cooling liquid. The filter isconnected to the liquid cooling circuit in parallel instead of in seriessince all the coolant fluid will not typically need to be filtered onevery revolution through the circuit. A flow restrictor 38 controls theamount of the liquid flowing through the filter. By way of example, theflow restrictor can have a 1:5 flow ratio (with the smaller flow flowingto the filter).

The heat exchanger 24 may be actively cooled by a fan 40. The fan 40blows ambient air across the heat exchanger 24, which is in thermalcontact with the cooling liquid flowing through the fluid circuit. Inthe exemplary embodiment of FIG. 1, the cooling circuit includes noactive cooling element other than the heat exchanger 24.

Including only a single fluid circuit with the attendant single pump andsingle heat exchanger significantly improves reliability and reduces thesize and complexity of the entire system. The closed fluid circuit canbe arranged as shown, with the various elements generally in series, orit could be arranged with one or more elements arranged in parallel, ora combination of the two.

FIG. 3 is a schematic block diagram of an exemplary control system forthe laser system. The control system includes a controller 60 operablyconnected to the laser head 30, a power supply 32, a discharge circuit64, a simmer module 66, and a display 68, which may have a touchinterface. The controller may also be connected to control the operationof the coolant pump 14 and heat sink fan 40. The controller 60 canreceive various inputs from (and provide outputs to) users through thetouch interface, switches, or a remote control device to allow users toaccess different functions of the system. For example, the system caninclude inputs to allow the user to activate and deactivate the laser,and operate the laser in various different modes, including modes thatvary the pulse length, pulse frequency, and instantaneous energy output.

The controller 60 is connected to a memory 70. As shown in FIG. 3, thememory 70 is physically adjacent to the controller, but canalternatively be connected to the controller without physical proximity,e.g., via a computer network such as the internet or a local areanetwork. The memory can comprise a variety of memory devices including,e.g., a USB flash drive, a secure digital (SD) card, a micro SD card, acompact flash (CF) memory, hard disk, or floppy disk. If networked, thememory may be physically remote from the device, e.g., attached to aseparate networked computer. Such a remote computer could be present ina central location in the same hospital as the surgical laser system, orcould be even more physically remote, for example at a location of thesystem's manufacturer, or a vendor responsible for maintenance of thesystem. The memory could also be linked directly to a patientselectronic medical records, or any other relevant record keepingdatabase, e.g., an occupational hazard database. The memory can collectand record data relevant to a particular procedure or type of procedure,a particular patient, and/or the particular system to which the memoryis attached or elements of that system. The memory can be used to recorda wide variety of types of information, for example: the dosage ofradiation emitted by the laser, duration of activation of the laser, thewavelength or wavelengths of light emitted by the laser, instantaneouspower emitted by the laser, the time averaged power emitted by thelaser, the time that a single element of the laser system (e.g., thepump, or the bulb) has been in use, the time that the entire system hasbeen in use, the number of times the system has been used, the timesince or time until a scheduled maintenance of the system or someelement of the system. Each of these variables can be recorded for asingle procedure, for a particular patient, or for all uses of theinstrument. Because the controller digitally outputs all relevant datato the memory, no surgical staff need to manually time and measure theapplication of the surgical laser in a surgery. This function can befully automated.

The system can be configured so that the surgical laser emitsnear-infrared (NIR) light generally in the range of 1000 nm to 1500 nm.In this wavelength range, especially at the long wavelength end of therange, the water present in tissue is highly absorptive, making cutting,ablating or vaporization of tissue effective. Also in this wavelengthrange, certain constituents of blood are highly absorptive and can beefficiently caused to clot. In particular, clotting of blood is mostefficiently achieved by NIR light of about 1100 nm. A good compromisewavelength that is effective both to encourage clotting when applied atlower intensities, and also to destroy tissue if applied at higherintensities, is about 1341 nm.

The emission port of the laser can have a variety of different openingangles. One preferred opening angle is about 17 degrees. By using asingle laser at about 1341 nm wavelength a surgeon can either cut orcoagulate tissue: by holding the emission port close to the tissue to bedestroyed, the surgeon can concentrate the emitted laser light intosmall area with high flux to cut; by holding the emission port fartherfrom the tissue, the surgeon can spread the laser light over a largerarea with lower flux in order to cause coagulation without cuttingtissue. The single laser can perform both tasks simply by being betweengreater and smaller distances from the tissue.

The power supply 32 can be in some embodiments a programmable powersupply, and can be made with more than one power output. While one poweroutput is connected to the laser 30, another output could be connectedto another electrical device. For example, the power supply 32 couldinclude an outlet arranged to provide RF power, e.g., for anelectrocautery or electrosurgery device 80 through an electrosurgery orelectrocautery module 82 as shown in FIG. 4. The electrosurgery orelectrocautery device 80 can thereby be conveniently powered by thepower supply 32 on the surgical laser system and integrated in the lasersystem. In either case, the programmable power supply could be switchedbetween a first mode in which power was supplied to the laser and asecond mode in which power was supplied to the electrosurgery orelectrocautery device 80 or another instrument. In one exemplary use anelectrocautery element is operated to cause cutting of tissue orcoagulation.

FIG. 5 schematically illustrates an exemplary laser head configurationin accordance with one or more embodiments. The laser head 30 includes anon-coaxial arrangement of a laser active rod of a surgical laser 102and a pointer laser 104. In the usual way, the surgical laser 102directs light into a fiber optic cable 106. The laser light is emittedfrom the emission port at a distal end of the fiber optic cable. Thepointer laser directs its visible light along a path that does notinclude the surgical laser, but instead is directed via optical elements(mirror 108 and beam splitter 110) onto the same path as the surgicallaser light. In the exemplary configuration of FIG. 5, the beam from thepointer laser is formed generally parallel to, but non-coaxial with, thesurgical laser beam, then turned 90 degrees by the mirror 108, thenturned 90 degrees again by a beam splitter (combiner) 110. The combinedsurgical and pointer laser beams are then directed through the fiberoptic 106 and emerge from the distal emission port. Visible laserpointer beams are important in the use of infrared surgical beams sincethe surgical beams are generally invisible. By setting the pointer laseroff the axis of the surgical laser, the entire system can be madesmaller and more portable. One particularly advantageous type of pointerlaser is a green laser having a wavelength of around 500 nm to around550 nm or a blue laser having a wavelength of around 400-500 nm. Redpointer lasers, e.g., 656 nm wavelength, are often used, but can bedifficult to see in a surgical context.

EXAMPLES

Medical laser systems can include a crystal-based laser operablyconnected to an emission port such that coherent light produced by thecrystal-based laser is directed out of the emission port, a power supplyoperably connected to the crystal-based laser, a controller operablyconnected to both the crystal-based laser and the power supply, aplurality of heat sinks, a fluid conduit forming a single closed fluidcircuit, a fluid substantially filling the fluid conduit, a pumpoperable to circulate the fluid through the fluid conduit, and a heatexchanger. In such systems at least one heat sink can be in thermalcontact with each of the crystal-based laser and the power supply, thefluid can be in thermal contact with each of the heat sinks, the heatexchanger can be in thermal contact with both (a) the fluid and (b)ambient surroundings, and the system can include no other active coolingmechanism.

In some such systems, the crystal-based laser can be, for example, apulsed laser and/or a YAP laser. In such systems, the pump can be amagnetic drive pump. In some such systems, the crystal-based laser canbe adapted to emit light having a wavelength in the range of 1000 to1500 nanometers, or for example about 1341 nanometers. In some suchsystems, the crystal-based laser can be adapted to emit with apredetermined power and wavelength into a predetermined solid anglesufficient to cause cutting of tissue when the emission port ispositioned at a first predetermined distance from the tissue, andcoagulation when the emission port is positioned at a second greaterpredetermined distance from the tissue. In some such systems thepredetermined solid angle has an opening angle of about 17 degrees. Insome such systems the fluid is a liquid, for example water.

Medical laser systems can include a crystal-based laser, a power supplyoperably connected to the crystal-based laser, a controller operablyconnected to both the crystal-based laser and the power supply, an inputoperably connected to the controller, and a memory operably connected tothe controller. In such systems the controller can be suitablyprogrammed to (a) when the input is activated by a user, activate thecrystal-based laser by causing the power supply to supply power to thelaser, and (b) record data in the memory, the data being indicative ofthe activation of the laser. The memory can be a removable memorymedium, for example a USB flash drive. In some embodiments, the memorycan be connected to the controller locally or through a computer networksuch as the internet or a local area network, or through a wirelesscommunications protocol such as Bluetooth.

In some such systems, the recorded data can be collated on at least oneof, or any combination of (i) a per procedure basis, (ii) a per patientbasis, and (iii) a per instrument basis. In some such systems, therecorded data can include at least one of, or any combination of (i) atotal dosage of electromagnetic radiation emitted by the crystal-basedlaser, (ii) a duration of the activation of the crystal-based laser,(iii) a wavelength or wavelengths of light emitted by the crystal-basedlaser, (iv) an instantaneous and/or time-averaged power of thecrystal-based laser, (v) the time that a single element of the systemhas been in use, (vi) the time that the entire system has been in use,and (vii) the time since or until scheduled system maintenance.

Medical laser systems can include a crystal-based laser, anelectrosurgery or electrocautery element, a power supply operablyconnected to both the crystal-based laser and the electrosurgery orelectrocautery element, the power supply being operable in a pluralityof modes, each mode supplying a different power level, a controlleroperably connected to the crystal-based laser, the electrosurgery orelectrocautery element, and the power supply, and an input operablyconnected to the controller. In such systems the controller can besuitably programmed to, when the input receives a first signal, causethe power supply to supply power to the crystal-based laser in a firstmode sufficient to cause the laser to cut or coagulate tissue, and whenthe input receives a second signal, cause the power supply to supplypower to the electrosurgery or electrocautery element in a second modesufficient to cause the electrosurgery or electrocautery element to cutor coagulate tissue. In some such systems, in the second mode the powersupply can supply power to the electrosurgery or electrocautery elementas a radiofrequency waveform. In some such systems the electrosurgery orelectrocautery element is a partially electrically insulated wire loop.

Medical laser systems can include a crystal-based laser configured, whenactivated, to emit laser light having wavelength in the range of 1000 to2000 nanometers, a pointer laser configured, when activated, to emitvisible green or blue laser light having a wavelength in the range of400 to 620 nanometers, a power supply operably connected to both thecrystal-based laser and the pointer laser, a controller operablyconnected to the power supply, the crystal-based laser and the pointerlaser, and an input operably connected to the controller. In suchsystems the controller can be suitably programmed to when the inputreceives a first signal, cause the power supply to supply power to thepointer laser and not to the crystal-based laser, and when the inputreceives a second signal, cause the power supply to supply power to boththe pointer laser and the crystal-based laser. In such systems thecrystal-based laser and pointer laser can be configured to be focused ona common target position.

A method of using a laser surgical system can make use of a system thatincludes a crystal-based laser operably connected to an emission portsuch that coherent light produced by the laser is directed out of theemission port, a controller operably connected to the crystal-basedlaser, and a power supply operably connected to the crystal-based laserand the controller. The system can be adapted to, when activated, emitfrom the emission port coherent light of a predetermined power andpredetermined wavelength into a predetermined solid angle. The methodcan include (1) positioning the emission port at a predetermined cuttingdistance from a tissue to be cut, (2) cutting the tissue to be cut byactivating the system while the emission port is at the predeterminedcutting distance from the tissue to be cut, (3) positioning the emissionport at a predetermined coagulation distance from a tissue to becoagulated, and (4) coagulating the tissue to be coagulated byactivating the system while the emission port is at the predeterminedcoagulation distance from the tissue to be coagulated.

Various processes of the controller described above may be implementedin software, hardware, firmware, or any combination thereof. Theprocesses are preferably implemented in one or more computer programsexecuting on the controller. Each computer program can be a set ofinstructions (program code) in a code module resident in the randomaccess memory of the controller. Until required by the controller, theset of instructions may be stored in another computer memory (e.g., in ahard disk drive, or in a removable memory such as an optical disk,external hard drive, memory card, or flash drive) or stored on anothercomputer system and downloaded via the Internet or other network.

Having thus described several illustrative embodiments, it is to beappreciated that various alterations, modifications, and improvementswill readily occur to those skilled in the art. Such alterations,modifications, and improvements are intended to form a part of thisdisclosure, and are intended to be within the spirit and scope of thisdisclosure. While some examples presented herein involve specificcombinations of functions or structural elements, it should beunderstood that those functions and elements may be combined in otherways according to the present disclosure to accomplish the same ordifferent objectives. In particular, acts, elements, and featuresdiscussed in connection with one embodiment are not intended to beexcluded from similar or other roles in other embodiments. Additionally,elements and components described herein may be further divided intoadditional components or joined together to form fewer components forperforming the same functions.

Accordingly, the foregoing description and attached drawings are by wayof example only, and are not intended to be limiting.

The invention claimed is:
 1. A medical laser system, comprising: acrystal-based laser; an electrosurgery or electrocautery device separatefrom said crystal-based laser and comprising an electrosurgery orelectrocautery module and an electrosurgery or electrocautery tool,wherein said tool can be independently held, maneuvered, and operatedrelative to the crystal-based laser; a power supply for powering thecrystal-based laser and the electrosurgery or electrocautery device; anda controller operably connected to the crystal-based laser, theelectrosurgery or electrocautery device, and the power supply, whereinthe controller is programmed to: (a) activate the crystal-based laser bycontrolling power supplied by the power supply to the laser responsiveto a laser activation input by a user; and (b) activate theelectrosurgery or electrocautery device by controlling power supplied bythe power supply to the electrosurgery or electrocautery deviceresponsive to an electrosurgery or electrocautery device activationinput by the user; wherein the controller is programmed to togglebetween activating only the crystal-based laser and activating only theelectrosurgery or electrocautery device responsive to user inputs. 2.The system of claim 1, wherein the crystal-based laser is a pulsed laserand/or a YAP laser.
 3. The system of claim 1, wherein the power supplysupplies power to the electrosurgery or electrocautery device as aradiofrequency waveform.
 4. The system of claim 1, wherein theelectrosurgery or electrocautery device is an electrocautery elementcomprising a partially electrically insulated wire loop.
 5. The systemof claim 1, wherein the crystal-based laser is configured, whenactivated, to emit laser light having wavelength in the range of 1000 to2000 nanometers; and wherein the system further comprises a pointerlaser configured, when activated, to emit visible green or blue laserlight having a wavelength in the range of 400 to 620 nanometers, whereinthe pointer laser and the crystal-based laser are configured to befocused on a common target position; wherein the power supply isconfigured to power the crystal-based laser and the pointer laser; andwherein the controller is programmed to: (a) activate the crystal-basedlaser by controlling power supplied by the power supply to the laserresponsive to a laser activation input from a user; and (b) activate thepointer laser by controlling power supplied by the power supply to thepointer laser responsive to a pointer laser activation input from theuser.
 6. The system of claim 5, wherein the controller is furtherprogrammed to adjust the intensity of green or blue laser light emittedfrom the pointer laser responsive to a user input.
 7. The system ofclaim 5, wherein pointer laser and the crystal-based laser are arrangedoffset from each other such that they generate non-coincident laserlight beams.
 8. The system of claim 5, further comprising opticalelements to direct laser light from the pointer laser and thecrystal-based laser on the same path through an emission port of thesystem.
 9. The system of claim 1, wherein the electrosurgery orelectrocautery tool is removably coupled to the electrosurgery orelectrocautery module.
 10. The system of claim 1, further comprising asingle liquid cooling system for cooling the power supply when thecrystal-based laser is active and when the electrosurgery orelectrocautery device is active.